Silica-reinforced ethylene propylene diene monomer/polypropylene thermoplastic vulcanizates with interfacial compatibilized by methylacrylate

Increasing the interfacial adhesion with compatibilizer has been proved to be an effective method to enhance the mechanical properties of composites. In this paper, sodium methacrylate (NaMAA) was introduced to enhance the interfacial adhesion between polypropylene (PP) and ethylene propylene diene monomer (EPDM) via the peroxide-induced dynamic vulcanization. NaMAA-induced compatibilization enhanced the phase interface efficaciously and reduced the diameter of EPDM particles from similar to 8 to similar to 4 mu m. Silica (SiO2) was used in the matrix to improve the mechanical properties of the thermoplastic vulcanizates (TPVs). It was found that SiO2 had little influence on the compatibility between EPDM and PP; however, it improved the tensile strength and stiffness of the TPVs without a severe reduction in the elasticity. The interfacial compatibility of modified EPDM/PP TPVs was verified by Fourier transform infrared, rubber process analyzer, and scanning electron microscope. With 3 wt% of NaMAA and 12 wt% of SiO2, the tensile strength improved from 8.5 to 12.7 MPa and the elongation at break was ranged from 320% to 410%.

Automated summary

Increasing the interfacial adhesion with compatibilizer such as NaMAA has been proven effective in enhancing the mechanical properties of composites, while introducing SiO2 in the matrix further improved the tensile strength and stiffness of the TPVs without compromising elasticity. The modified EPDM/PP TPVs showed enhanced interfacial compatibility as verified by various analytical methods.